The present invention relates to a data processing system having a multiprocessor configuration and, more particularly, to a technique effectively applied to a data processing system in which data processes performed by processor cores have to be synchronized.
In a multiprocessor system having a plurality of processor cores, the processor cores execute processes individually, thereby realizing parallelization of the processes, shortening of the process time, and the like. In such a multicore system, depending on a process, a synchronization is necessary among the processor cores. Patent documents 1 to 3 disclose related arts of synchronizing operations of a plurality of processor cores in a multiprocessor system.
Patent document 1 discloses a multiprocessor system in which a synchronizing processor increments or decrements a value in a common region, a processor to be synchronized increments or decrements a value in a local region and, when the value in the common region reaches the value in the local region, the processor to be synchronized starts or restarts process synchronously with operation of the synchronizing processor. Patent document 2 discloses a multicore processor for comparing an address value of a program executed by a synchronizing processor core with an address value of a program executed by a processor core to be synchronized and, according to a result of the comparison, controlling whether the program of the processor core to be synchronized can be executed or not. Patent document 3 discloses an information processor having a configuration in which a plurality of processor cores are coupled in series via a common memory.
As other related arts, patent documents 4 and 5 disclose, not a multiprocessor system, but systems of decoding and reproducing coded data in a moving image including a video image and sound coded. Patent document 4 discloses a method of obtaining a speed difference between a video decoding/reproducing process and an audio decoding/reproducing process by measuring time since completion of audio data decoding/reproducing process until end of process of decoding/reproducing a video frame to be measured in unit time and, according to the process speed difference, adjusting a start timing of a video image decoding/reproducing apparatus, thereby synchronizing the video image and sound. Patent document 5 discloses a method of detecting time stamp information in sound and a video image in compression moving image data and generating an interrupt signal on the basis of the detected information to realize synchronization between sound and a video image.